I've played a ton of games featuring succubi, and honestly, while some do include them with a dick, it's not as common as people make it out to be. The ones that do tend to fall into the futa category get more attention because those games cater to a broader audience. That wider appeal often translates into higher Patreon support, which in turn boosts the budget and visibility of those titles.
Lesbian succubi, on the other hand, are much more rare, not because the concept lacks appeal, but because it's harder to market female x female content. Most players prefer to immerse themselves in fantasies where they play as a guy with a dick, followed by futa or femboy characters that still offer that phallic self-insertion. The further the fantasy strays from that baseline, the harder it becomes for players to connect with it and scratch that specific itch.
It all becomes apparent when you type 'futa' into tags as well, you see a demonstrably smaller number of games appear in the first place.